It is not a matter of whether or not they are right, they feel that they are irrefutably right and should push their system, even if no one else wants it, since they must have some wisdom that no one else possesses. I do not think they are from Jupiter, maybe their ego makes them believe they are from there.
Certainly the world has been dominated by Empires during the history we know. But that does not make the United States an Empire, in fact, the United States fought against the last true empire that existed that was Nazi Germany.
Not an empire then? Ok. I'll stick to the empire thing. Nazi Germany was an Empire? because they called themselves the third reich? (as reich meaning realm or empire) at the most they were a project of an empire. So you agree there were empires, lots of them, but now, as in RIGHT now, no empire?
Let's agree to disagree then...
Nazi Germany was an Empire, because the term refers to a form of government and state structure, Nazi Germany, although it had no emperor, had an equally powerful figure as "Führer", and tried by all means will return a quasi-feudal system but with greater freedom economy.
The United States is not an empire, it is a federal constitutional republic. If you mean that the United States is the first world power and the dominant power, I give you the reason, in the bad and in the good that this implies.